I recently for the first time recorded a GoToWebinar presentation. GoToWebinar, from Citrix, provides the option for their own proprietary output or WMV. I took the WMV option, to make it easier for my viewers, and give me the option to clean up any errors in the presentation.
Upon completion of the recording, I brought the WMV file into Windows Movie Maker. The source was 80MB (1 hr), and Windows Movie Maker split it into 8 pieces of various lengths. I performed normal edits, chopping out some dead space at two points, increasing the overall audio level, and adding intro and exit info. So far, so good.
Upon trying to save my project is where I ran into troubles. Trying several different settings, closing other programs to free memory, and rebooting -- nothing worked; it would not output. I then decided to try another computer, and realized I needed GoToWebinars own codec -- this was my first clue that I may not be able to solve this problem.
I tried two different encoders and importing into Camtasia -- still no better. Back on my original PC, I found some additional ideas from http://sam.charrington.com - somuchtolearn... so little time! I tried the recommended transcoding application that comes with GoToWebinar, which failed; I tried Windows Media Encoder, which looked promising, but it too failed.
I've come to the conclusion that GoToWebinar is not a good solution for recording presentations. I've had previous experience with WebEx, and have successfully been able to perform the same functions that I am unable to do with GoToWebinar. (Monthly fees for WebEx are known to be higher.)
If presenting with GoToWebinar is your only option, I recommend a screen capture of the presentation with a 3rd party tool such as TechSmith's Camtasia or Adobe Captivate. This usually requires a capture on a different PC than the one that is hosting the presentation. There are also many free and open source solutions such as Jing (from TechSmith), Windows Media Encoder (I discover in this process that it can be used for screen capture, though I have not tried myself), or CamStudio.